Add a Logstash 'V1' Formatter

https://logstash.jira.com/browse/LOGSTASH-675
Fix a bug and a broken test.

Very embarrassing.
Merge Logstach V1 logic into the main Logstash formatter, add a parameter to the constructor to specify version

Defaults to version '0'.
Remove separate V1 formatter from the read me.
Merge remote-tracking branch 'idio/master'
Formatting fixes
Fix test bootstrap autoloader

The previous `require_once` statement returns `true` when it loads the
autoload file rather than an instance of `ClassLoader`. Changing the
statement to `require` returns the instance needed to add the Monolog
test directory.
Merge pull request #232 from adlawson/fix-bootstrap

Small fix to test bootstrap
Add PHPUnit to dev dependencies

The easier it is for people to contribute, the better. Relying on a
global install of PHPUnit via PEAR doesn't sit well with some
developers. As other dev dependencies are installed via composer, why
not add PHPUnit itself to the list?
Merge pull request #233 from adlawson/dep-phpunit

Add PHPUnit to dev dependencies
logging levels phpdoc added
Merge pull request #235 from peterkokot/patch-1

Logging levels phpdoc added
more composer installation info added
version of monolog changed to minimal version
Merge pull request #236 from peterkokot/patch-docs

Composer installation info added
moved stubs up so line numbers don't change
added level to introspection processor
Merge pull request #238 from kriswallsmith/master

added level support to introspection processor
mongoCollection attribute visibility changed to protected so subclasses can access this attribute to query the database
Add missing blod style to log level listing